Heavy vehicles, in excess of 20,000 lb GVW are commonly used in clearing roadways and other surfaces of snow and ice. Most of these vehicles are used by municipalities or large private entities with a need to clear a large area, such as a highway, airport, or other similar structure. Often these vehicles utilize a material spreader to treat these surfaces to prevent future buildup of additional snow and ice in addition to snow and ice removal equipment. Most often, the material spreader is used to broadcast road salt, sand, cinders, or a combination of one or more of these materials over the newly plowed or cleared surface.
Current spreaders, particularly those used in these heavy duty trucks, tend to incorporate features such as a hopper having sloped or angled interior sides which direct material down to a central, longitudinal conveyor, which in turn drives the material to the rear of the spreader. Here it exits the hopper and falls through a chute onto a horizontally oriented spinner, which broadcasts the material outward to cover an area of the ground surface significantly wider than the vehicle or material spreader itself.
These prior art systems are known to be effective in evenly spreading material over a large surface in a short period of time, and often at high speeds. Despite their known effectiveness, many of these systems still suffer from defects, including the need for regular maintenance such as lubrication and replacement of wearable parts. Furthermore, without proper maintenance, these systems are prone to clogging or breaking, as well as decreased flow rate of material and inconsistent distribution of materials.
Other known devices spread liquid material, including de-icing liquids, brines, or other chemical applications. It is common to combine the features of a particulate material spreader with a liquid material spreader to allow flexibility in application of these materials depending on the specifics of a particular surface or job. Systems incorporating both a liquid and particulate material spreader suffer the same defects listed above, but the inclusion of spreaders for both material types creates limited space for each which in turn reduces load capacity. Lack of space on the rear of a vehicle can also cause the operator to eliminate desired features, additional components, and/or safety equipment from the vehicle.
Finally, given that the industry predominately uses salt and brine mixtures in these material spreaders, corrosion from standing salt and/or salt spray tends to pose additional problems.
What is needed is a spreader which requires less maintenance and is less susceptible to corrosion, is capable of delivering multiple material types, and maximizes the usable space on the rear of the vehicle, while maintaining flexible equipment options and not reducing the load capacity or safety of the spreader. Further advantages to such a system include favorable changes to the ease and cost of manufacturing as well as less down time due to maintenance and/or breakage.